Analytical Chemistry Lab, Gembloux Agro-Bio Tech, University of Liège, Gembloux 5030, Belgium.
Department of Agricultural, Forest and Food Sciences, University of Turin, 10124, Italy.
J Chromatogr A. 2023 Aug 2;1702:464095. doi: 10.1016/j.chroma.2023.464095. Epub 2023 May 22.
This work presents the investigation of the use of heptane as an alternative and less toxic mobile phase to the most used hexane for triacylglycerols (TAGs) analysis in silver ion high-performance liquid chromatography (Ag-HPLC). The impact of column temperature (in the 5 °C-35 °C range) on the retention and resolution of five pairs of regioisomers relevant for the confectionery industry was investigated using a heptane-based mobile phase modified with acetonitrile (ACN). The retention behaviour was compared for a standard TAG mixture and an interesterified cocoa butter. The temperature effect previously observed with hexane-based mobile phases was confirmed for this new system, and it was also observed that the ACN concentration had an important impact on the strength of the temperature effect, with a higher ACN concentration leading to a lesser impact of temperature on the TAGs' elution behaviour. In general, the study allowed to conclude on the equivalence of hexane and heptane for TAGs regioisomers separation in Ag-HPLC, independently of the used temperature or the ACN concentration. In addition, the applicability of heptane-based mobile phases for the separation of TAGs regioisomers was demonstrated on three other confectionary fat samples, namely palm olein, interesterified palm olein, and interesterified shea olein.
本工作研究了庚烷作为替代物的用途，与最常用的己烷相比，庚烷的毒性更小，可用于银离子高效液相色谱（Ag-HPLC）分析三酰基甘油（TAGs）。使用含乙腈（ACN）的庚烷基流动相，研究了柱温（5°C-35°C 范围内）对 5 对对映异构体保留和分离的影响，这些对映异构体与糖果工业有关。对标准 TAG 混合物和酯交换可可脂进行了保留行为比较。对于这个新系统，证实了先前在基于己烷的流动相中观察到的温度效应，并且还观察到 ACN 浓度对温度效应的强度有重要影响，ACN 浓度越高，温度对 TAG 洗脱行为的影响越小。总的来说，该研究得出结论，无论使用的温度或 ACN 浓度如何，庚烷和己烷均可用于 Ag-HPLC 中 TAG 对映异构体的分离，二者等效。此外，庚烷基流动相在分离其他三种糖果脂肪样品（即棕榈仁油、酯交换棕榈仁油和酯交换乳木果油）中的 TAG 对映异构体的适用性也得到了证明。
